Primality proof for n = 13883:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=631.html>631 is prime.</a>
<br>b^((n-1)/631)-1 mod n = 1637, which is a unit, inverse 441.
<p>(631) divides n-1.
<p>(631)^2 > n.
<p>n is prime by Pocklington's theorem.